Year	% net
1972	16.28677
1973	16.59849
1974	17.09416
1975	18.44464
1976	19.3182
1977	19.65102
1978	20.87823
1987	42.08292
1995	41.82443
2001	49.59
2002	50.80151
2003	53.46558
2004	54.89742
2005	53.3964
2006	57.5779
2007	64.8416
2008	64.02634
2009	64.76545
2010	66.64897
2011	72.91917
2012	74.17695
2013	75.36034
2014	75.21275
2015	75.77185
2018	78.73112